Memory devices typically include memory elements for storing data. “Flash” electrically erasable and programmable read only memories (EEPROMs) include an electrical storage gate layer for altering a transistor threshold voltage. Thus, such devices sense data values based on a static transistor threshold voltage.
Devices having one time programmable elements, such as “anti-fuse” elements, can program an element by creating a non-reversible conductive path. Thus, such devices may sense data values based on a static resistance of the cell.
Conventional conductive bridge random access memories (CBRAMs) can include memory elements (sometimes referred to as programmable metallization cells, PMCs) that may be programmed (or erased) to different resistance levels. Many PMC cells can have a metal-insulator-metal (MIM) structure. In one state (e.g., erased), substantially no current can flow through the MIM structure. In another state (e.g., programmed), a conductive path can be formed through the insulator layer. Accordingly, such memory devices may sense data values based on a resistance of a storage element (e.g., PMC).
In all of these conventional examples, the sense operations measure a property of the memory cell (e.g., threshold voltage, path conductivity) that remains substantially unchanged over the duration of the operation.